134 



remained unknown to naturalists. We climb- 

 ed, not without some difficulty, the small hill 

 whence the subterraneous rivulet descends. 

 We saw, that the grotto was perceptibly con- 

 tracted, retaining only forty feet in height ; 

 and that it continued streching to the North- 

 east, without deviating from its primitive di- 

 rection, which is parallel to that of the great 

 valley of Caripe. 



In this part of the cavern, the rivulet deposes 

 a blackish mould, very like the matter, which 

 in the grotto of Muggendorf, in Franconia, is 

 called the earth of sacrifice*. We could not 

 discover, whether this fine and spongy mould 

 fall through the cracks, which communicate 

 with the surface of the ground above ; or be 

 washed down by the rainwater, that penetrates 

 into the cavern. It was a mixture of silex, 

 alum in, and vegetable detritus. We walked 

 in thick mud to a spot, where we beheld with 

 astonishment the progress of subterraneous vege- 

 tation. The seeds, which the birds carry into 

 the grotto to feed their young, spring up wher- 

 ever they can fix in the mould, that covers the 

 calcareous incrustations. Blanched stalks, with 

 some half formed leaves, had risen to the height 

 of two feet. It was impossible to ascertain the 



* Opfer-erde of the cavern of Hole Berg (mountain pierced 

 entirely through). 



